I don't think so. Thought I watched something where they said it was almost impossible for someone to shoot of that drain.

There have been so many rumblings about Chicago being involved with the Kennedy assassination, that I sort of stopped listening to most of them.

IIRC, Chicago was involved with the bay of pigs invasion, so there is some documented connection between the CIA and Chicago.

Did Chicago play a small part in conspiracy? Perhaps. Will there ever be any proof? Probably not.